Smoking among some adults dropped dramatically in past three decades

The proportion of adult smokers dramatically decreased during the past three decades in at least one metropolitan area -- with more quitting and fewer picking up the habit, according to research presented at the American Heart Association's Scientific Sessions 2010.

The Minnesota Heart Survey, a population-based, serial cross-sectional study of trends in cardiovascular risk factors, included between 3,000 and 6,000 participants in each of its six surveys. Examining the smoking trends in adults 25 to 74 years old in the Minneapolis/St. Paul metropolitan area from 1980 to 2009, researchers found:

The number of current smokers was cut in half, decreasing from 32.8 percent to 15.5 percent in men and from 32.7 percent to 12.2 percent in women, with greater decreases among adults with higher income and more education.

Current smokers were smoking less. The age-adjusted average number of cigarettes smoked per day decreased from 23.5 to 13.5 in men and 21.1 to 10.0 in women.

Fewer Americans picked up the habit, with ever-smokers dropping from 71.6 percent to 44.2 percent in men and from 54.7 percent to 39.6 percent in women.

Men continued to start smoking regularly at an average age of just under 18 years over the study period.

While women have also decreased cigarette use, the age they start smoking regularly has dropped from 19 to just under 18.

"The proportion of people who smoke cigarettes has decreased dramatically in the past 30 years," said Kristian B. Filion, Ph.D., lead author of the study and Postdoctoral Associate in the Division of Epidemiology and Community Health at the University of Minnesota in Minneapolis. "One interesting finding was the differences in the subgroups. Individuals with more education had much greater decreases in smoking than those with less education."

The percent of current smokers among men with more than high school education decreased from 29 percent to 11 percent. In contrast, current smoking in men who had just completed high school or had less education decreased from 42 percent to 31 percent.

In women the numbers were different, but the trend was similar.

Limitations of this work included the exclusion of people aged 18 to 24 years and the study of a population that was predominantly white and fairly educated.

The study didn't address the impact of legislative changes such as increases in cigarette taxes. Smoking cessation efforts have made an impact; however, more emphasis needs to be placed on individuals in lower income brackets and those with less education, Filion said.

"Present interventions are less effective in those of lower socioeconomic status," he said. "This group may not have the same access to medical care or the public health messages in the news media just aren't reaching them."

There also needs to be a focus on younger women because societal changes and advertising may be having a negative influence, he said. "The prevalence of smoking has been decreasing, but it remains a public health issue. We need to have a better grasp on designing specific interventions for specific groups. A one-size-fits-all approach to stop smoking may not be as successful in some groups."

Despite 15 years of smoking abstinence, former heavy smokers have a significantly increased risk of heart failure, according to an Alabama study.

Researchers from the University of Alabama at Birmingham found that during 12 years of follow-up, the incidence of heart failure among never-smokers was 20 percent versus 29 percent among former smokers (who quit smoking 15 or more years ago) but smoked 32 or more pack years -- a 44 percent increase in relative risk over non-smokers.

Compared with never-smokers, former smokers, who quit 15 or more years earlier but were among the highest quartile in pack years of smoking, also had an increased risk of heart attack and death from all causes. The risk of the former smokers in the lowest three quartiles in pack years of smoking was similar to that of never-smokers.

A 2004 Surgeon General's Report on health consequences of smoking concluded that "after 15 years of abstinence, the risk of coronary heart disease is similar to that of persons who have never smoked." According to the researchers, findings from the current study suggest that this benefit may not extend to heavy smokers.

These findings are based on the Cardiovascular Health Study, funded by the National Heart, Lung, and Blood Institute, which included 5,338 participants with no prevalent heart failure. The analysis focused on 1,297 people who had quit smoking 15 or more years prior and 2,558 people who have never smoked.

Smoking cessation increases high density lipoprotein (HDL) cholesterol - a good type of cholesterol - despite the weight gain commonly associated with quitting, according to a randomized study.

Despite gaining approximately 10 pounds after smoking cessation, compared to the 1.5 pound gain experienced by those who continued to smoke, quitters had an improved cholesterol profile. Those who quit smoking had increases in HDL cholesterol of 2.4 mg/dl compared to no change in continuing smokers. Researchers also found increases in total and large HDL particles in those who quit when compared to smokers. After adjustment, smoking abstinence was independently associated with increases in HDL cholesterol and total HDL particles.

The HDL responses to smoking cessation were not affected by baseline smoking intensity nor smoking cessation strategy, implying that even light smokers experience improvements in good cholesterol when they quit. Nuclear magnetic resonance spectroscopy determined cholesterol profiles before and one year after the target smoking quit date in 923 individuals in a smoking cessation study.

Smoking cessation did not affect low density lipoproteins (LDL), the bad cholesterol, or their size, researchers reported. Increases in HDL may be responsible for part of the reduced cardiovascular disease risk observed after smoking cessation, the researchers said.

After a program that included medication (varenicline), individualized counseling and referral to outpatient cessation programs, 82 percent of smokers had quit at 12 months.

Carbon monoxide levels dropped from 44 parts per million (ppm) at baseline to 3 ppm after one year of smoking cessation.

Those who quit smoking had significant drops in blood pressure, total cholesterol and no increase in body weight. These changes led to an overall reduction in cardiovascular risk from 4.2 to 0.8 after 12 months.

The reduction in blood pressure and total cholesterol without weight gain resulted in a significant decrease in the estimated 10-year risk for heart attack, researchers said.

Smoking cessation in the study was high, demonstrating the promise of an integrated smoking cessation program, researchers said. The program's success shows the importance of this type of treatment in an internal medicine department setting, researchers said.

Abstract 15138/P2075 -- Parents who smoke at home increase their children's levels of oxidation injury

Parents who smoke at home may place their children at risk of oxidative injury -- possibly increasing their risk of cardiovascular disease, according to Austrian researchers.

Oxidative stress leads to inflammation and an increased risk of vascular damage and narrowing of the arteries.

During cholesterol screening tests, the researchers found that children of smokers had higher levels of an oxidative stress marker than children of nonsmoking parents. Children of smoking parents had 13.2 picograms/milliliter in plasma while children of nonsmoking parents had 7.1 pg/ml.

After parents were advised to quit smoking, researchers tested the children (7 to 9 years old) at three and six months. When the parents continued to smoke, the levels of the marker remained unchanged. But when parents quit, the levels of the marker significantly dropped to that of children of nonsmokers after three months.

The positive effect was more pronounced when mothers rather than fathers quit smoking and most effective when both parents quit smoking. The effect was not different in girls or boys.

Statements and conclusions of study authors that are presented at American Heart Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The association makes no representation or warranty as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations are available at www.heart.org/corporatefunding.

NR10-1133 (SS10/Filion/smoking)

Editor's Note: The American Heart Association supports adequate funding for state tobacco cessation and prevention programs, robust coverage in private and public health plans for tobacco cessation, clean indoor air laws and excise taxes.
www.heart.org/tobaccocontrol.

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